Lift-bridge.



No. 657,l22. Patented Sept. 4, I900.

F. LA Pumfe. LIFT BRIDGE.

(Applies-titan filed June 6, 1900.)

2 Shouts-Sheet I.

(No Model.)

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'No. 657,!22. Patented Sept. 4, I900. F. LA PUINTE.

LIFT BRIDGE.

(Application filed June 6, 1900.)

(No Model.) 2 Shuts-Sheet 2.

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m: warns Mn'ms w, PnofouYno. WhSNIKGTON. n cy PATENT OFFICEQ FRANCOIS LA POINTE, OF CHICAGO, ILLINOIS, ASSIGNOR OF TWO-TI-IIRDS TO ALBERT G. SOHERER AND IVILLIAM BRET'SNYDER, OF SAME PLACE.

LIFT-BRIDGE.

SPECIFICATION forming part of Letters Patent No. 657,122, dated September 4, 1900. Application filed June 6,1900. $erlal No. 19,220. (No model.)

To all whom it iii/(by concern.-

Beit known that I, FRANCOIS LA POINTE, a citizen of the United States, residing in Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Lift-Bridges, of which the following is a specification,

This invention is intended to provide means whereby what are commonly known as lift or bascule bridges maybe kept in perfect balance in all posit-ions, so that the operating devices by which they are raised and lowered are at no time required to do heavy duty.

The invention consists in providing the bridge with a series of pivots or centers upon which it may swing in succession, moving from one to the next as the center of gravity shifts during the movement of the bridge. These centers are arranged in parallel positions at the required distances apart, and preferably are three in number, with the center one raised above the others,and the bridge is provided with a corresponding series or plurality of open bearings or sockets arranged and adapted to receive the pivots in their proper order, so that the bridge will be sustained by the pivots in successive order and be easily operated in all positions.

The nature of the invention will be fully understood from the accompanying drawings, in which- Figure 1 is a side view of a bridge equipped with my improvement. Fig. 2 is an enlarged partial side view, and Figs. 3, 4, 5, and 6 are detail views of the pivotal supporting parts of the bridge.

In said drawings, 10 represents the movable or lifting section of the bridge, and 11 is a pier of masonry on which said lifting section is supported. In this pier is a recess into which the counterbalance 12 of the bridge descends when the section 10 is raised.

The pivotal supports of the lifting section are located on pier 11 near the waterway spanned by said section and may consist of a series of fixed or stationary pivots 13, 14, and 15, all mounted in parallel positions and at short distances apart in a pillow-block l6 and preferably provided with antifrictionrollers 17, 1S, and 19, respectively. As will be noticed, pivot 14, which is the middle one of the series, is raised above the plane of. the other two. The bridge-section is provided with a series of sockets or open boxes 20, 21, and 22, formed in the block 23, attached to said section and corresponding in number to the pivots and each adapted to receive or set down over one of the pivot-rollers. lVhen the bridge is in its normal position, pivot 13 will be entered in socket 20. WVhen raised, the pivot 14 and socket 21 will gradually assume the burden and pivot 13 and socket 20 will gradually separate, and when the bridge reaches its fully open position socket 22 will have set down over pivot 15 and socket 21 and pivot 14 will have separated. The raised and lowered positions of the bridge are both indicated at Fig. 2. It will be understood that these pivots, sockets, and blocks are duplicated in such manner as may be needed, and I prefer to employ them at each side of the bridge in order that any swerving laterally at the free end may be prevented.

For operating the bridge any suitable means may be employed; but I prefer to employ cables 30, secured at both ends to the counterbalance end of the bridge, as shown at 31 and 32, and encircling a power-drum 33, driven by gearing 34 35, (be. These cables (at least two of which are desirable) are given the proper direction by means of pulleys 36, 37, 38, and 39, and they serve to carry power from the drum for lifting or lowering the bridge, according to the direction in which the drum is rotated, rotating the latter so as to draw on that portion of the cables passing over pulleys 37, 38, and 39, causing opening of the bridge, and rotating it so as to draw on the part passing over pulley 36, acting to close the bridge.

The operation of the invention will be fully understood from the description already given. -It willbe seen that by providing a plurality of successively-acting centers and bearings upon which the bridge may swing the shifting of the center of gravity of the bridge does not materially affect its balance, so that the operating power need never be required to do excessive duty.

The centers are well adapted topreventany longitudinal shifting of the bridge at all times,and during the movements ofthe bridge each socket engages its center before the last previously-acting socket and center have separated. They are made strong, so that each center may, with its duplicate'eenter or centers, sustain the entire weight of the bridge. In practice the centers are located several feet apart, as the center of gravity of the bridge shifts not less than twelve feet in some cases while opening and closing. Of course I do not wish to be limited to three centers, as obviously two centers might be employed insome cases, and in others a greater number than three could be used; but I believe three to be a desirable number in the majority of bridges, and in no case should the number be increased much beyond three.

I claim" 1. The lift or bascule bridge having a limited number of widely-separated centers upon which it is supported and swings in succession while being opened and closed, substantially as specified.

2. The lift or bascule bridge having a Hillited number of widely-separated centers upon 7 which it is supported and swings in succession while being opened and closed,- such centers being provided with antifriction-rollers, substantially as specified.

3. The lift or bascule bridge having alimited number of widely-separated centers upon which it is supported and swings in succession while being opened and closed, such centers being located at different levels, substantially as specified.

4. The lift or bascule bridge having three centers on which it swings in succession, the center pivot being raised above the others, substantially as specified.

5. The lift or bascule bridge having a limited number of widely-separated centers upon which it is supported and swings in succession while being opened and closed, and also having a corresponding number of open sockets with which the several centers may suecessively engage, substantially as specified.

FRANCOIS LA POINTE.

Witnesses:

WILLIAM BRETSNYDER, ALBERT G. SCHERER. 

